ice40: Add support for SB_GB_IO

During packing we replace them by standard SB_IO cells and create the
'fake' SB_GB that matches that IO site global buffer connection.

It's done in a separate pass because we need to make sure the nextpnr iob
have been dealt first so we have our final Bel location on the SB_IO.

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/ice40/archdefs.h b/ice40/archdefs.h
index 8dcf0365..2bffe667 100644
--- a/ice40/archdefs.h
+++ b/ice40/archdefs.h
@@ -150,6 +150,7 @@ struct ArchCellInfo
         struct
         {
             bool lvds;
+            bool global;
             // TODO: clk packing checks...
         } ioInfo;
         struct